Stationary Josephson effect in a short multi-terminal junction

Abstract

We study the dc Josephson effect and the density of states in a multiterminal structure of cross-type geometry which consists of four superconducting electrodes connected by one-dimensional normal or ferromagnetic wires. We find that the Josephson current $I_{Jz}$ has a sinusoidal dependence on the phase difference $\phi_z$ between the superconductors in the horizontal wire with a critical current $I_c$ that can be varied by changing the phase difference $\phi_y$ between the superconductors in the vertical wire. The period of the function $I_{Jz}(\phi_z)$ depends on the ratio of the interface resistances $R_{Sn,z}/R_{Sn,y}$ being equal to $2\pi $ if this ratio is small and equal to $4\pi $ in the opposite limit. We also calculate the amplitudes of both the singlet and the odd-frequency triplet component in the system under consideration. The triplet component amplitude may be significantly larger than the amplitude of the singlet component.